Idiosyncratic surgical practice patterns may contribute to unwarranted variation in the use of laparoscopy and partial nephrectomy (PN) among patients with early-stage renal cell carcinoma (RCC). In order to test this hypothesis, we will explore the following specific aims: 1) To evaluate geographic variation in the use of laparoscopic surgery among patients with RCC; 2) To characterize geographic variation in the use of PN among patients with RCC; and 3) To assess for an interaction between the use of laparoscopy and the use of PN. Linked data from SEER and Medicare will be used to identify a national sample of incident kidney cancer cases diagnosed between 1998 and 2002. Temporal trends in annual incidence rates for RCC- specific laparoscopy and PN will be calculated and compared for individual hospital referral regions, adjusted for relevant covariates. Interactions between the use laparoscopy and PN will be evaluated a priori. This data will provide more precise characterization of unwarranted variation in the use of laparoscopy and PN among patients with early-stage kidney cancer and may, in turn, motivate patient-, provider- and policy-level interventions aimed at making the surgical treatment of RCC both more effective and more patient-centered. [unreadable] [unreadable] [unreadable]